[sudo-users] Giving access to one app for all users

[Micha]

|    Is there anything I should post?

Yes, who is in the group admin and who is in users ?
Please give a breif description of the membership status 
concerning these groups, of those 3 (?) logins you have tried.
Also please if some account has empty password (passwd -d).

I didn't get the beginning of the thread (some filter problems).
I may miss some information you already provided.
I have to admit i joined the list because i have many
questions myself ;) 
And do you want me to cc to you always ?